JP6767451B2 - Connection part seal structure and seal member - Google Patents

Description

The present invention relates to a connection portion seal structure and a seal member that connect a first connection portion and a second connection portion via a seal member.

Conventionally, in a semiconductor manufacturing apparatus, a sealing member is arranged at a connecting portion of parts constituting a pipe, a fluid control device, or the like to prevent the fluid from leaking to the outside. For example, in the connection portion seal structure described in Patent Document 1 and Patent Document 2, an annular protrusion and a tapered surface are formed on the connection end surface of the pipe, while an annular groove and a tapered surface are formed on the seal member, and the annular projection is formed into an annular groove. It is configured by press-fitting and pressing the tapered surfaces together. Further, in the connection portion seal structure described in Patent Document 1, the taper angle of the tapered surface provided on the seal member is larger than the taper angle of the tapered surface provided on the connection end surface, and the pressure contact allowance between the tapered surfaces is larger. It is enlarged at a position near the wall surface of the flow path away from the base end of the annular protrusion.

Japanese Patent No. 4465254 Japanese Patent No. 5134573

However, the connection portion seal structure described in Patent Document 1 and Patent Document 2 has the following problems. In the connection portion seal structure described in Patent Document 1, the pressure contact allowance between the tapered surfaces is large at a position close to the flow path wall surface away from the base end portion of the annular projection. Therefore, in the connection portion seal structure described in Patent Document 1, a large pressure contact force is applied to the vicinity of the flow path wall having a thin wall thickness on the connection end surface, and the flow path wall surface may bend toward the center side of the flow path. In this case, the connection portion sealing structure described in Patent Document 1 may narrow the flow path or reduce the sealing force between the tapered surfaces due to bending. Further, Patent Document 2 describes that the annular protrusion is press-fitted into the annular groove to bring the tapered surfaces into contact with each other, but the tapered shape and problems are not specified.

The present invention is for solving the above-mentioned problems, and an object of the present invention is to provide a connection portion sealing structure and a sealing member having high sealing performance while suppressing deformation of a flow path.

One aspect of the present invention has the following configuration. (1) The first connection portion and the second connection portion are connected via a seal member, and both or one of the connection end face of the first connection portion and the connection end face of the second connection portion is the connection. A flow path wall that opens to the end face, an annular protrusion that protrudes radially outside the flow path wall along the axial direction of the flow path wall, and an inner mounting groove that is provided inside the annular protrusion in the radial direction. In a connection portion seal structure in which the sealing member is formed in an annular shape and the annular groove is press-fitted into both end faces or one end surface, the inner mounting groove is a base of the annular projection. A support piece that is provided at a sharp angle with respect to the annular protrusion on the radial inside of the end portion and has an inner tapered portion that connects to the flow path wall, and that supports the inner peripheral surface end portion of the seal member is the inner portion. The tapered portion is provided in an annular shape along the flow path wall, and the radial wall thickness of the portion located on the proximal end side of the annular projection is the radial thickness of the portion located on the tip end side of the annular projection. Being larger than the thickness, the inner peripheral surface of the sealing member has an inner pressure contact tapered portion that is formed along an end portion located on the end surface side where the annular groove opens and is inclined so as to press contact with the inner taper portion. That is, the inner taper pressure contact allowance at which the inner pressure contact tapered portion presses against the inner taper portion is characterized in that the base end portion side of the annular protrusion is larger than the tip end side of the annular protrusion.

In the connection portion seal structure having such a configuration, the taper angle of the internal pressure contact taper portion provided on the seal member is made smaller than the taper angle of the inner taper portion provided on the connection portion. The pressure contact force of the portion that is in pressure contact with the tapered portion to seal is large on the annular projection side and small on the flow path side. That is, the pressure contact force of the portion where the inner pressure contact tapered portion and the inner taper portion are pressure-welded and sealed increases in the portion where the wall thickness of the connecting portion is thick, and decreases in the portion where the wall thickness is thin. As a result, when the first connecting portion and the second connecting portion are connected via the seal member, the amount of bending of the acute-angled portion provided between the inner tapered portion and the flow path wall of the connecting portion is reduced. Therefore, according to the connection portion seal structure having the above configuration, the connection portion does not greatly inflate the flow path wall inward in the radial direction due to the repulsive force of the seal member, so that narrowing of the flow path can be prevented or suppressed. Moreover, the surface pressure applied by the inner tapered portion to the inner pressure welding tapered portion is generated toward the sealing portion between the annular projection and the pressure welding allowance of the annular groove. Therefore, the sealing force generated in the inner taper pressure contact allowance in which the inner taper portion and the inner pressure contact taper portion are in pressure contact with each other and the seal pressure contact allowance in which the annular projection and the inner wall of the annular groove are sealed increases. Therefore, according to the connection portion sealing structure having the above configuration, it is possible to reliably prevent fluid leakage and have high sealing performance.

(2) In the configuration according to (1), the connection end surface provided with the inner mounting groove has an outer mounting groove provided on the radial outer side of the annular protrusion, and the sealing member has the outer mounting groove. It is preferable to have an outer pressure contact allowance that presses outward in the radial direction with respect to the inner wall of the above, and that the outer pressure contact allowance is smaller than the inner taper pressure contact allowance that the inner pressure contact taper portion presses against the inner taper portion.
(3) The first connection portion and the second connection portion are connected via a seal member, and both or one of the connection end face of the first connection portion and the connection end face of the second connection portion is the connection. A flow path wall that opens to the end face, an annular protrusion that is formed in an annular shape along the outer periphery of the flow path wall and protrudes along the axial direction of the flow path wall, and an annular protrusion that is provided inside the annular protrusion in the radial direction. In a connection portion seal structure comprising the inner mounting groove provided, the sealing member is formed in an annular shape, and the annular projection is press-fitted into both end faces or one end face, the inner mounting groove is provided. The annular groove is provided on the radially inner side of the base end portion of the annular protrusion so as to have an inner tapered portion connected to the flow path wall, and the inner peripheral surface of the seal member has the annular groove. It has an internal pressure welding tapered portion that is formed along the end portion located on the end face side to be opened and is inclined corresponding to the inner tapered portion, and the taper angle of the internal pressure welding tapered portion is the taper angle of the inner tapered portion. It is smaller, the connection end surface provided with the inner mounting groove has an outer mounting groove provided on the radial outer side of the annular protrusion, and the sealing member is radially outside the inner wall of the outer mounting groove. It is characterized by having an outer pressure welding allowance that is pressed in the direction, and the outer pressure welding allowance is smaller than the inner taper pressure welding allowance that is pressed against the inner tapered portion.

In the connection portion seal structure having such a configuration, the outer pressure welding allowance is made smaller than the inner taper pressure welding allowance, so that the repulsive force of the seal member is reduced as compared with the case where the outer pressure welding allowance and the inner taper pressure welding allowance are provided in the same manner. To do. Therefore, according to the connection portion seal structure, when the first connection portion and the second connection portion are connected via the seal member, the first connection portion and the second connection portion are deformed by the repulsive force of the seal member. This can be suppressed and a decrease in sealing force can be prevented.

(4) In the configuration according to (2) or (3), the position of the outer pressure welding allowance is the base end portion of the annular projection rather than the seal pressure welding allowance where the inner wall of the annular groove and the annular projection are in pressure contact. It is preferably on the side.

In the connection portion seal structure having such a configuration, the surface pressure received from the inner wall of the outer mounting groove to the outer pressure welding allowance is generated toward the seal pressure welding allowance in which the annular projection and the inner wall of the annular groove are pressure-welded. Therefore, the sealing force is increased. Therefore, according to the connection portion sealing structure having the above configuration, it is possible to reliably prevent fluid leakage and have high sealing performance.

(5) In the configuration according to any one of (2) to (4), the external mounting groove is provided on the radial outer side of the base end portion of the annular projection at an acute angle with respect to the annular projection. It is preferable to have an outer tapered portion.

In the connection portion seal structure having such a configuration, the outer taper portion makes it easier for the outer pressure welding allowance to fall toward the base end portion side of the annular projection. Therefore, according to the connection portion seal structure having the above configuration, the surface pressure generated in the seal pressure welding allowance increases, so even if the outer pressure welding allowance is made smaller than the inner taper pressure welding allowance, the sealing force increases and fluid leakage is ensured. Can be prevented.

(6) In the configuration according to any one of (2) to (5), the outer peripheral surface of the seal member is externally pressure-welded formed along an end portion located on the end surface side where the annular groove opens. It is preferable to have a tapered portion.

In the connection portion seal structure having such a configuration, the outer pressure welding allowance is more likely to fall toward the base end portion side of the annular projection due to the external pressure welding tapered portion. Therefore, according to the connection portion seal structure having the above configuration, the surface pressure generated in the seal pressure welding allowance increases, so even if the outer pressure welding allowance is made smaller than the inner taper pressure welding allowance, the sealing force increases and fluid leakage is ensured. Can be prevented.

(7) In the connection portion sealing structure according to any one of (2) to (6), the outer peripheral surface of the sealing member located on the outer side in the radial direction is along the axial direction of the outer mounting groove. It is preferable to include a surface close to the surface.

In the connection portion seal structure having such a configuration, for example, it is assumed that excessive attachment / detachment of the annular groove and the annular protrusion is repeated, or the first and second connection portions and the seal member are exposed to an abnormal temperature change. In this case, even if the pressure contact force of the outer pressure contact allowance is reduced, the outer peripheral surface of the seal member and the surface along the axial direction of the outer mounting groove are in contact with each other, and the deformation of the seal member is suppressed. At this time, since the outer pressure welding allowance is assisted to be pressurized to the annular projection side, the connection portion sealing structure having the above configuration can secure the sealing force as in the initial state and the temperature change in the normal state.

(8) In the configuration according to any one of (1) to (7), having a clamp member for fixing the first connecting portion and the second connecting portion via the sealing member. The first connection portion and the second connection portion are formed with a clamp groove to which the clamp member is mounted and have a flange shape, the shape of the first connection end surface provided in the first connection portion, and the first. It is preferable that the shapes of the second connection end faces provided in the two connection portions are the same, and that the shape of both end faces of the seal member is the same.

In the connection portion seal structure having such a configuration, the first and second connection portions form a flange shape by forming a clamp groove, and the rigidity is low. However, the repulsive force of the seal member is reduced. Therefore, when the first connecting portion and the second connecting portion are connected via the seal member, the deformation of the first connecting portion and the second connecting portion so as to warp is suppressed. Therefore, the connection portion seal structure having the above configuration becomes compact without the need to increase the wall thickness of the first and second connection portions and the clamp member to increase the rigidity.

(9) In the connection portion sealing structure according to any one of (1) to (8), the sealing member is a base of the annular projection when the annular projection is press-fitted into the annular groove. It is preferable to form an annular gap with the end portion.
(10) It is a sealing member used in the connection portion sealing structure according to any one of (1) to (9). According to the seal member having such a configuration, the repulsive force when arranged between the first and second connecting portions is suppressed, so that the deformation of the flow path formed in the first and second connecting portions is deformed. It is possible to demonstrate high sealing performance while suppressing it.

Therefore, according to the present invention, it is possible to provide a connecting portion sealing structure and a sealing member having high sealing performance while suppressing deformation of the flow path.

It is sectional drawing of the connection part seal structure which concerns on 1st Embodiment of this invention. It is an enlarged view of the part A of FIG. It is a front side perspective view of the seal ring which concerns on 1st Embodiment of this invention. It is an enlarged cross-sectional view around the seal main body part of the seal ring shown in FIG. It is a figure explaining the connection method of the 1st and 2nd connection part, and shows a temporary fixing position. It is a figure explaining the connection method of the 1st and 2nd connection part, and shows the time of press-fitting start. It is a figure explaining the connection method of the 1st and 2nd connection part, and shows the time when the press-fitting is completed. It is a figure explaining the force relation generated in each pressure welding allowance of a seal main body part. It is a figure which shows the surface pressure analysis result of the connection part seal structure shown in FIG. It is sectional drawing which shows the connection part seal structure which concerns on 2nd Embodiment of this invention. It is an enlarged sectional view around the seal main body part of the seal ring of 2nd Embodiment. The state where the work of press-fitting the first and second annular protrusions into the first and second annular grooves is completed is shown. It is a figure explaining the force relation of the seal part in the connection part seal structure shown in FIG. It is a figure which shows the surface pressure analysis result of the connection part seal structure shown in FIG. It is a connection part seal structure which concerns on 3rd Embodiment of this invention, and is the enlarged sectional view around the seal main body part. It is a front view of the seal ring of 3rd Embodiment. It is a top view of the seal ring of 3rd Embodiment. It is a rear view of the seal ring of the 3rd embodiment. It is a right side view of the seal ring of 3rd Embodiment. FIG. 16 is a sectional view taken along line BB in FIG. It is a CC sectional view of FIG. It is a DD sectional view of FIG. It is a front side perspective view of the seal ring of 3rd Embodiment. This is a first modification of the seal body. This is a second modification of the seal body. This is a third modification of the seal body. It is a front view of the modification of a seal ring. It is a top view of the seal ring shown in FIG. 27. It is a rear view of the seal ring shown in FIG. 27. It is a right side view of the seal ring shown in FIG. 27. It is JJ sectional view of FIG. FIG. 27 is a cross-sectional view taken along the line KK of FIG. It is LL sectional view of FIG. It is a front side perspective view of the seal ring shown in FIG. 27.

Hereinafter, embodiments of the connection portion seal structure and the seal member according to the present invention will be described with reference to the drawings.

(First Embodiment)
<Structure of connection part seal structure>
FIG. 1 is a cross-sectional view of the connection portion seal structure 1 according to the first embodiment of the present invention. FIG. 2 is an enlarged view of part A of FIG. The first and second inner taper pressure welding allowances P1 and P2, the first and second outer pressure welding allowances P3 and P4, the first and second inner seal pressure welding allowances P5 and P6, and the first one shown in FIG. And the second outer seal pressure welding allowances P7 and P8 are actually crushed.

As shown in FIG. 1, the connection portion seal structure 1 is used, for example, at the connection portion between the first pipe 10 and the second pipe 20 through which the gas used in the semiconductor manufacturing apparatus flows. In the first pipe 10 and the second pipe 20, the first connection end surface 12 of the first connection portion 11 and the second connection end surface 22 of the second connection portion 21 are butted with each other via the seal ring 30, and the first and second connections are made. The connected state is maintained by mounting the clamp member 40 on the outer periphery of the portions 11 and 21.

The first and second pipes 10 and 20, the seal ring 30, and the clamp member 40 are made of a resin having a similar coefficient of linear expansion. For example, when the chemical solution having a high temperature exceeding 200 ° C. and the cleaning solution at room temperature are switched and flowed through the first and second pipes 10 and 20, the first and second connection portions 11 and 21 and the seal ring 30 and the clamp member 40 are used. This is to maintain the sealing performance by keeping the expansion and contraction generated in the above to the same level. The first and second pipes 10 and 20 are made of a fluororesin having excellent corrosion resistance and strength, such as PTFE. The resins of the first and second pipes 10 and 20 may be the same or different. The seal ring 30 is made of a fluororesin having excellent corrosion resistance, such as PFA. On the other hand, the clamp member 40 is stronger than the first and second connecting portions 11 and 21 in order to maintain the connected state of the first and second connecting portions 11 and 21 against the repulsive force of the seal ring 30. It is made of a corrosion-resistant fluororesin.

<Structure of 1st and 2nd connection parts>
As shown in FIG. 1, the first connection portion 11 and the second connection portion 21 are provided in the same shape. In the first and second connecting portions 11 and 21, the first and second clamp grooves 13 and 23 for mounting the clamp member 40 are formed in an annular shape along the outer peripheral surface. Therefore, the first and second connecting portions 11 and 21 are provided in a flange shape. That is, at the outer edges of the first and second connecting portions 11 and 21, the wall thickness between the first and second connecting end faces 12 and 22 and the first and second clamp grooves 13 and 23 is thin.

As shown in FIG. 2, the first connection end surface 12 is open to the first flow path wall 16a of the first flow path 16. In the first connection end surface 12, the first mounting groove 14 is formed in an annular shape along the outer circumference of the first flow path wall 16a. On the bottom wall of the first mounting groove 14, the first annular protrusion 17 is formed in an annular shape along the outer circumference of the first flow path wall 16a. The first annular protrusion 17 projects along the axial direction of the first flow path wall 16a. Therefore, the first mounting groove 14 includes the first inner mounting groove 14c provided on the radial inner side of the first annular protrusion 17 and the first outer mounting groove 14d provided on the radial outer side of the first annular protrusion 17. It has.

The first inner mounting groove 14c has a first inner tapered portion 14a inside the base end portion 17a of the first annular projection 17 in the radial direction. The first inner tapered portion 14a is provided at an acute angle with respect to the first annular projection 17, and generates a surface pressure F1 (see FIG. 8) that presses the seal main body portion 31 of the seal ring 30 toward the first annular projection 17. To do. The first inner tapered portion 14a is connected to the first flow path wall 16a. Therefore, the first connection portion 11 is provided with a first support piece 18 that supports the seal main body portion 31 of the seal ring 30 along the first flow path wall 16a. The first support piece 18 has a triangular cross-sectional shape in the axial direction, and the thickness of the portion located on the base end portion 17a side of the first annular projection 17 is the portion located on the tip end portion 17b side of the first annular projection 17. It is larger than the wall thickness.

The first outer mounting groove 14d has a first outer tapered portion 14b on the radial outer side of the base end portion 17a of the first annular projection 17. That is, the first outer tapered portion 14b is a wall surface 19 in the direction of the flow path wall axis located on the radial outer side of the first outer mounting groove 14d, and is located on the opposite side of the opening of the first mounting groove 14. It is provided on the side part. The first outer tapered portion 14b is provided at an acute angle with respect to the first annular projection 17, and generates a surface pressure F2 (see FIG. 8) that presses the seal main body portion 31 of the seal ring 30 toward the first annular projection 17. To do.

The second connection end surface 22 includes a second flow path wall 26a, a second mounting groove 24, a second inner tapered portion 24a, a second outer tapered portion 24b, a second inner mounting groove 24c, a second outer mounting groove 24d, and a second. The annular protrusion 27 and the second support piece 28 are provided on the first connection end surface 12, the first flow path wall 16a, the first mounting groove 14, the first inner tapered portion 14a, the first outer tapered portion 14b, and the first inner. It is provided in the same manner as the mounting groove 14c, the first outer mounting groove 14d, the first annular protrusion 17, and the first support piece 18. As described above, since the second connection end face 22 has the same shape as the first connection end face 12, the description thereof will be omitted.

<Structure of seal member>
FIG. 3 is a front perspective view of the seal ring 30 according to the embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of the seal ring 30 shown in FIG. 3 around the seal main body 31. In FIG. 4, only the shape of the cross-sectional portion is shown and the hatching is omitted in order to make the drawing easier to see.

The seal ring 30 shown in FIG. 3 is molded by injection molding. The seal ring 30 is formed along the ring-shaped seal main body 31, the overhang 32 provided so as to project outward from the outer peripheral surface of the seal main body 31, and the outer peripheral edge of the overhang 32. The grip portion 33 is provided. The seal body 31 is an example of a seal member.

As shown in FIG. 5, the grip portion 33 is arranged outside the first and second connecting portions 11, 21. As shown in FIG. 3, in the grip portion 33, the locking portions 33c and 33d that are locked to the protrusions 15 and 25 of the first and second connecting portions 11 and 21 shown in FIG. 5 are extended portions. It is provided in 33a and 33b.

As shown in FIG. 2, the seal ring 30 is designed so that the inner diameters are substantially the same as the inner diameters of the first and second flow path walls 16a and 26a, and the inner peripheral surface 31 g is the first and second streams. A flow path is formed together with the road walls 16a and 26a.

As shown in FIGS. 2 and 4, the seal main body 31 is mounted in the first and second mounting grooves 14 and 24 of the first and second connecting portions 11 and 21. The seal main body 31 has an H-shaped cross-sectional shape in the axial direction. That is, in the seal main body 31, the first annular groove 31a is formed on one end surface in the axial direction, and the second annular groove 31b is formed on the other end surface in the axial direction. Therefore, the seal main body 31 is provided with a first inner annular wall 31v radially inside the first annular groove 31a, and a first outer annular wall 31m provided radially outside the first annular groove 31a. Further, the seal main body 31 is provided with a second inner annular wall 31w on the radial inside of the second annular groove 31b, and a second outer annular wall 31n on the radial outer side of the second annular groove 31b.

As shown in FIG. 2, the radial width dimension W21 of the first annular groove 31a is smaller than the radial width dimension W11 of the first annular projection 17. As a result, the first annular groove 31a is provided with the first inner seal pressure contact allowance P5 on the inner peripheral surface located on the inner side in the radial direction, and the first outer seal pressure contact allowance P7 on the inner peripheral surface located on the outer side in the radial direction. Has been done. Further, in the second annular groove 31b, the radial width dimension W22 is smaller than the radial width dimension W12 of the second annular projection 27. As a result, the second annular groove 31b is provided with the second inner seal pressure contact allowance P6 on the inner peripheral surface located on the inner side in the radial direction, and the second outer seal pressure contact allowance P8 on the inner peripheral surface located on the outer side in the radial direction. Has been done. That is, the seal main body 31 is sealed by pressing the first and second inner annular walls 31v and 31w with the first and second annular protrusions 17 and 27, and the first and second inner seal pressure welding allowances P5 and P6. And the first and second outer seal pressure welding allowances P7 and P8 for sealing by pressing the first and second outer annular walls 31m and 31n with the first and second annular protrusions 17 and 27.

As shown in FIGS. 2 and 4, the opening of the first annular groove 31a is tapered by a first positioning portion 31c that guides and positions the first annular projection 17 in the axial direction with respect to the first annular groove 31a. It is formed in a shape. The inlet of the first positioning portion 31c is provided with the first large diameter portion 31e by forming the radial width dimension larger than the radial width dimension of the first annular projection 17. Due to the first large diameter portion 31e, as shown in FIG. 2, the seal main body portion 31 forms a gap S1 in an annular shape between the first inner annular wall 31v and the base end portion 17a of the first annular projection 17. , A gap S5 is formed in an annular shape between the first outer annular wall 31m and the base end portion 17a of the first annular projection 17. In the gaps S1 and S5, the first inner annular wall 31v and the first outer annular wall 31m form the first and second annular projections 17, 27 during and after the first and second connecting portions 11 and 21 are attracted. Allows it to deform to the side and absorbs the repulsive force of the seal body 31.

Further, as shown in FIGS. 2 and 4, in the opening of the second annular groove 31b, the second positioning portion 31d is provided in the same manner as the first positioning portion 31c and the first large diameter portion 31e of the first annular groove 31a. And the second large diameter portion 31f are formed. Due to the second large diameter portion 31f, as shown in FIG. 2, the seal main body portion 31 forms a gap S2 in an annular shape between the second inner annular wall 31w and the base end portion 27a of the second annular protrusion 27. A gap S6 is formed in an annular shape between the second outer annular wall 31n and the base end portion 27a of the second annular projection 27, and is generated during and after the first and second connecting portions 11 and 21 are attracted. The repulsive force is absorbed by the gaps S2 and S6.

The inner peripheral surface 31g of the seal main body 31 has a first internal pressure welding tapered portion 31h formed along an end portion located on the end surface side where the first annular groove 31a opens. Further, on the inner peripheral surface 31g, a second internal pressure contact tapered portion 31i is formed along an end portion located on the end surface side where the second annular groove 31b opens.

As shown in FIGS. 2 and 4, the first internal taper portion 31h has an inclination corresponding to the first inner taper portion 14a and is pressure-welded to the first inner taper portion 14a. As shown in FIG. 2, the taper angle θ11 of the first internal pressure welding tapered portion 31h is smaller than the taper angle θ1 of the first inner tapered portion 14a. Here, the taper angle θ11 refers to the angle formed by the inner peripheral surface located inside the first large diameter portion 31e in the radial direction and the first internal pressure contact tapered portion 31h, and the taper angle θ1 is the taper angle θ1 of the first annular protrusion 17. It refers to the angle formed by the inner peripheral surface located on the inner side in the radial direction and the first inner tapered portion 14a. That is, as for the first inner taper pressure contact allowance P1 in which the first inner pressure contact tapered portion 31h is in pressure contact with the first inner taper portion 14a, the portion P1a located on the tip end side of the first inner annular wall 31v is the first inner annular. It is provided larger than the portion P1b located on the base end side of the wall 31v. That is, the pressure contact force F5 (see FIG. 8) of the first inner taper pressure contact allowance P1 increases toward the base end portion 17a side of the first annular projection 17. The first support piece 18 has a large wall thickness on the base end portion 17a side and high rigidity. Therefore, the strong portion of the first support piece 18 corresponds to the portion where the pressure contact force F5 of the first inner taper pressure contact allowance P1 becomes large, and the first support piece 18 is not easily deformed by the pressure contact force F5.

On the other hand, as shown in FIGS. 2 and 4, the second inner pressure contact tapered portion 31i has an inclination corresponding to the second inner taper portion 24a and is pressure contacted with the second inner taper portion 24a. As shown in FIG. 2, the taper angle θ12 of the second internal pressure welding tapered portion 31i is smaller than the taper angle θ2 of the second inner tapered portion 24a. Here, the taper angle θ12 refers to the angle formed by the inner peripheral surface located inside the second large diameter portion 31f in the radial direction and the second internal pressure welding tapered portion 31i, and the taper angle θ2 is the angle formed by the second annular protrusion 27. It refers to the angle formed by the inner peripheral surface located on the inner side in the radial direction and the second inner tapered portion 24a. That is, in the second inner taper pressure contact allowance P2 in which the second inner pressure contact taper portion 31i is in pressure contact with the second inner taper portion 24a, the portion P2a located on the tip end side of the second inner annular wall 31w is the second inner annular. It is provided larger than the portion P2b located on the base end side of the wall 31w. That is, the pressure contact force F6 (see FIG. 8) of the second inner taper pressure contact allowance P2 increases toward the base end portion 27a side of the second annular projection 27. The second support piece 28 has a large wall thickness on the base end portion 27a side and high rigidity. Therefore, the strong portion of the second support piece 28 corresponds to the portion where the pressure contact force F5 of the second inner taper pressure contact allowance P2 becomes large, and the second support piece 28 is less likely to be deformed by the pressure contact force F5.

On the other hand, on the outer peripheral surface 31j of the seal main body portion 31, the first external pressure contact tapered portion 31p is formed along the end portion located on the end surface side where the first annular groove 31a opens. Further, on the outer peripheral surface 31j, a second external pressure contact tapered portion 31q is formed along an end portion located on the end surface side where the second annular groove 31b opens.

As shown in FIGS. 2 and 4, the first external pressure contact tapered portion 31p is outside the radial direction with respect to the outer peripheral surface located on the radial outside of the first external mounting groove 14d provided in the first connection portion 11. A first outer pressure welding allowance P3 for pressure welding in the direction is provided. The taper angle θ13 of the first external pressure welding tapered portion 31p is smaller than the taper angle θ3 of the first outer tapered portion 14b. Here, the taper angle θ13 refers to the angle formed by the outer inner wall located on the radial outer side of the first large diameter portion 31e and the first external pressure contact tapered portion 31p, and the taper angle θ3 is the diameter of the first annular protrusion 17. The angle formed by the outer peripheral surface located on the outer side in the direction and the first outer tapered portion 14b. Therefore, the pressure contact force F6 (see FIG. 8) of the first outer pressure contact allowance P3 becomes larger as it is closer to the base end portion 17a of the first annular projection 17. The first connecting portion 11 has no void near the base end portion 17a and has high strength. Therefore, the portion of the first connecting portion 11 having strength corresponds to the portion where the pressure contact force F6 of the first outer pressure contact allowance P3 becomes large. Moreover, the first outer annular wall 31m tends to be deformed so as to tilt the tip portion radially outward. Therefore, the seal main body 31 can maintain the sealing force while reducing the pressure contact force F6.

The taper angle θ13 of the first external pressure welding tapered portion 31p is smaller than the taper angle θ11 of the first internal pressure welding tapered portion 31h. As a result, a gap S3 for absorbing the deformation of the first outer annular wall 31m is formed between the first external pressure contact tapered portion 31p and the first outer tapered portion 14b. Further, the tip surface 31t of the first outer annular wall 31m is provided lower than the tip surface 31r of the first inner annular wall 31v. Therefore, in the seal main body portion 31, the contact area between the first external pressure contact taper portion 31p and the first outer taper portion 14b is smaller than the contact area between the first internal pressure contact taper portion 31h and the first inner taper portion 14a. The pressure contact force F6 of the first outer pressure contact allowance P3 is smaller than the pressure contact force F5 of the first inner taper pressure contact allowance P1.

The first external pressure contact tapered portion 31p and the outer peripheral surface 31j are connected via the first inclined portion 31k. The first inclined portion 31k is provided with a taper angle θ15 larger than the taper angle θ13 of the first external pressure welding tapered portion 31p to increase the rigidity of the first outer annular wall 31m.

As shown in FIGS. 2 and 4, the second external pressure contact tapered portion 31q is outside the radial direction with respect to the outer peripheral surface located on the radial outside of the second external mounting groove 24d provided in the second connecting portion 21. A second outer pressure welding allowance P4 for pressure welding in the direction is provided. The taper angle θ14 of the second external pressure welding tapered portion 31q is smaller than the taper angle θ4 of the second outer tapered portion 24b. Here, the taper angle θ14 refers to the angle formed by the outer inner wall located on the radial outer side of the second large diameter portion 31f and the second external pressure contact tapered portion 31q, and the taper angle θ4 is the diameter of the second annular protrusion 27. The angle formed by the outer peripheral surface located on the outer side in the direction and the second outer tapered portion 24b. Therefore, the pressure contact force F6 (see FIG. 8) of the second outer pressure contact allowance P4 becomes larger as it is closer to the base end portion 27a of the second annular projection 27. The second connecting portion 21 has no gap near the base end portion 27a and has high strength. Therefore, the strong portion of the second connecting portion 21 and the portion where the pressure contact force F6 of the second outer pressure contact allowance P4 becomes large correspond to each other. Moreover, the second outer annular wall 31n tends to be deformed so that the tip end portion is tilted outward in the radial direction. Therefore, the seal main body 31 can maintain the sealing force while reducing the pressure contact force F6.

The taper angle θ14 of the second external pressure welding tapered portion 31q is smaller than the taper angle θ12 of the second internal pressure welding tapered portion 31i. As a result, a gap S4 for absorbing the deformation of the second outer annular wall 31n is formed between the second outer pressure contact tapered portion 31q and the second outer tapered portion 24b. Further, the tip surface 31u of the second outer annular wall 31n is provided lower than the tip surface 31s of the second inner annular wall 31w. Therefore, in the seal main body portion 31, the contact area between the second external pressure contact taper portion 31q and the second outer taper portion 24b is smaller than the contact area between the second internal pressure contact taper portion 31i and the second inner taper portion 24a. The pressure contact force F6 of the second outer pressure contact allowance P4 is smaller than the pressure contact force F5 of the second inner taper pressure contact allowance P2.

The second external pressure contact tapered portion 31q and the outer peripheral surface 31j are connected via the second inclined portion 31l. The second inclined portion 31l is provided with a taper angle θ16 larger than the taper angle θ14 of the second external pressure welding tapered portion 31q to increase the rigidity of the second outer annular wall 31n.

<How to connect the first and second connections>
Subsequently, a method of connecting the first connecting portion 11 and the second connecting portion 21 will be described. 5A, 6th, and 7th are views for explaining a connection method of the connection portion. FIG. 8 is a diagram for explaining the force relationship generated in each pressure welding allowance P1 to P8 of the seal main body 31. In FIGS. 5 to 8, only the shape of the cross-sectional portion is shown in order to make the drawings easier to see. Further, in FIG. 8, hatching is omitted.

As shown in FIG. 5, in the seal ring 30, the locking portion 33c is locked to the protruding portion 15 of the first connecting portion 11, and the locking portion 33d is locked to the protruding portion 25 of the second connecting portion 21. As a result, it is temporarily fixed to the first and second connection portions 11 and 21 so as not to fall off. In this state, the first and second annular protrusions 17, 27 have not reached the first and second positioning portions 31c, 31d.

Therefore, for example, a jig (not shown) is engaged with the first and second clamp grooves 13 and 23, and the pulling load in the direction of bringing the first and second connection end faces 12 and 22 closer is applied to the first and second connection portions 11. , 21. Then, the first and second annular protrusions 17, 27 are guided along the axis by the first and second positioning portions 31c, 31d to the first and second annular grooves 31a, 31b, and as shown in FIG. The tip portions 17b and 27b begin to be press-fitted into the first and second inner seal pressure welding margins P5 and P6 and the first and second outer seal pressure welding margins P7 and P8 of the seal main body 31. In the seal ring 30, the first and second annular grooves 31a and 31b are expanded by the first and second annular protrusions 17 and 27, and the first and second inner annular walls 31v and 31w and the first and second outer annulars are formed. The walls 31m and 31n try to be deformed so as to fall on the opposite sides of the first and second annular protrusions 17 and 27.

When the first and second connecting portions 11 and 21 are continuously attracted by a jig (not shown), the seal main body portion 31 has the first and second inner tapered portions 14a and 24a and the first and second internal pressure contact tapered portions 31h and 31i. The first and second outer taper portions 14b and 24b are in sliding contact with the first and second external pressure contact tapered portions 31p and 31q. Then, the first and second inner annular walls 31v, 31w and the first and second outer annular walls 31m, 31n have the first and second inner tapered portions 14a, 24a and the first and second outer tapered portions 14b, 24b. Deformation is suppressed by the surface pressure received from.

As shown in FIG. 7, when the press-fitting is completed, the inner walls of the first and second annular grooves 31a and 31b are sealed to the first and second annular protrusions 17, 27, and the seal ring 30 is sealed in the first and second annular protrusions 17, 27. The pressure welding tapered portions 31h and 31i seal the first and second inner tapered portions 14a and 24a, and the first and second external pressure welding tapered portions 31p and 31q seal the first and second outer tapered portions 14b and 24b. This prevents fluid from leaking between the first and second connecting portions 11 and 21.

That is, as shown in FIG. 8, in the seal ring 30, the first and second inner seal pressure contact allowances P5 and P6 are pressed against the inner peripheral surfaces of the first and second annular protrusions 17 and 27 to be in close contact with each other. Seal loads F3 and F4 are generated when the first and second outer seal pressure contact allowances P7 and P8 are pressed against the outer peripheral surfaces of the first and second annular protrusions 17 and 27 and come into close contact with each other. Then, the seal ring 30 receives the surface pressures F1 from the first and second inner tapered portions 14a and 24a with respect to the respective pressure contact forces F5 of the first and second internal pressure contact tapered portions 31h and 31i, respectively. The first and second inner taper pressure welding margins P1 and P2 are crushed to perform sealing, and contribute to an increase in the sealing load F3. Further, the seal ring 30 receives the surface pressures F2 from the first and second outer tapered portions 14b and 24b with respect to the respective pressure contact forces F6 of the first and second external pressure contact tapered portions 31p and 31q, respectively. The first and second outer pressure welding margins P3 and P4 are crushed to contribute to an increase in the seal load F4.

In this case, since the taper angles θ11 and θ12 of the first and second internal pressure welding tapered portions 31h and 31i are smaller than the taper angles θ1 and θ2 of the first and second internal tapered portions 14a and 24a, the first and second The pressure contact forces F5 of the inner taper pressure contact allowances P1 and P2 and the pressure contact forces F6 of the first and second outer pressure contact allowances P3 and P4 are close to the base end portions 17a and 27a of the first and second annular protrusions 17 and 27. It's getting bigger. The first and second connecting portions 11 and 21 are not easily deformed because the wall thickness and strength in the vicinity of the base end portions 17a and 27a are large. Therefore, in the connection portion seal structure 1, the first and second connection portions 11 and 21 are less likely to be deformed by the pressure contact forces F5 and F6 of the seal main body portion 31.

In particular, the first and second support pieces 18 and 28 that support the inner peripheral surface 31 g of the seal main body 31 have a triangular cross-sectional shape in the axial direction and low strength. However, in the first and second inner taper pressure contact allowances P1 and P2, the pressure contact force F5 becomes large in the thick portions of the first and second support pieces 18 and 28. Therefore, the connection portion seal structure 1 is not easily deformed so that the first and second support pieces 18 and 28 bulge toward the first and second flow paths 16 and 26 due to the pressure contact force F5. Therefore, according to the connection portion seal structure 1 of the present embodiment, it is possible to avoid or suppress that the sealing force is lowered or the flow path is narrowed due to the deformation of the first and second support pieces 18 and 28.

Moreover, the seal main body 31 has the maximum surface pressures F1 and F2 at the tips of the first and second inner annular walls 31v and 31w and the tips of the first and second outer annular walls 31m and 31n, which are most easily deformed. Become. Then, the surface pressure acts toward the first and second inner seal pressure welding allowances P5 and P6 and the first and second outer seal pressure welding allowances P7 and P8. That is, the surface pressure is the portion of the first and second inner seal pressure contact allowances P5 and P6 and the first and second outer seal pressure contact allowances P7 and P8 that are close to the first and second flow paths 16 and 26, that is, It acts toward the vicinity of the connection position between the first and second annular grooves 31a and 31b and the first and second positioning portions 31c and 31d to maintain or raise the seal loads F3 and F4.

Further, the seal main body 31 is provided with the first and second inner taper pressure contact allowances P1 and P2 on the base end portions 17a and 27a side of the first and second inner seal pressure contact allowances P5 and P6, and the first and second outer sides are provided. By providing the pressure welding allowances P3 and P4 on the base end portions 17a and 27a side of the first and second outer seal pressure welding allowances P7 and P8, the directions in which the surface pressures F1 and F2 act can be more reliably performed on the first and second inner sides. It is possible to direct the seal pressure welding margins P5 and P6 and the first and second outer seal pressure welding margins P7 and P8.

Therefore, the connection portion seal structure 1 is provided on the inner peripheral side of the first and second annular protrusions 17 and 27 even if the pressure contact force F5 is reduced to such an extent that the deformation of the first and second support pieces 18 and 28 can be suppressed. It becomes possible to maintain or increase the acting seal load F3. Further, even if the pressure contact force F6 is reduced, it is possible to maintain or improve the seal load acting on the outer peripheral side of the first and second annular protrusions 17 and 27.

Therefore, according to the connection portion seal structure 1 of the present embodiment, the fluid can be reliably prevented from leaking and can have high sealing performance.

As shown in FIG. 1, the first and second connecting portions 11 and 21 are maintained in a state in which the first and second connecting portions 11 and 21 are attracted to each other via the seal main body 31 by a jig (not shown). , The clamp member 40 is mounted on the first and second clamp grooves 13, 23.

As shown in FIG. 8, the first and second connecting portions 11 and 21 have the first and second annular protrusions 17 and 27 in the radial direction rather than the inside of the first and second annular protrusions 17 and 27 in the radial direction. On the outside, there are flanges along the first and second connecting end faces 12, 22. Therefore, in the first and second connecting portions 11 and 21, pressure contact forces acting radially outward from the first and second external pressure contact tapered portions 31p and 31q to the first and second outer taper portions 14b and 24b. The strain generated by F6 tends to appear in the shape of the flange-shaped portion. Therefore, when the first and second outer pressure welding allowances are, for example, the same size as the first and second inner taper pressure welding allowances, the first and second connection end faces 12 and 22 are warped on the outer peripheral surface side. There is a risk of deformation.

On the other hand, in the connection portion seal structure 1 of the present embodiment, the first and second outer pressure contact allowances P3 and P4 are smaller than the first and second inner taper pressure contact allowances P1 and P2, and the pressure contact force F6 is the pressure contact force F5. It's getting smaller. Fluid leakage is mainly prevented by the sealing portion between the inner peripheral surfaces of the first and second annular protrusions 17 and 27 and the inner walls of the first and second annular grooves 31a and 31b. Therefore, the first and second outer pressure welding allowances P3 and P4 do not need to be as large as the first and second inner taper pressure welding allowances P1 and P2. That is, the first and second outer pressure welding allowances P3 and P4 can be reduced to such an extent that the deformation of the first and second outer annular walls 31m and 31n can be suppressed and a predetermined seal load F4 can be maintained. ..

By minimizing the sizes of the first and second outer pressure welding allowances P3 and P4 in this way, the connection portion seal structure 1 of the present embodiment has the first and first and first positions against the elastic force of the seal body portion 31. 2 The pulling load that pulls the connecting parts 11 and 21 is reduced. That is, when the first and second connection portions 11 and 21 are attracted through the seal main body 31, the repulsive force generated by the seal main body 31 is reduced. Therefore, according to the connection portion seal structure 1 of the present embodiment, it is possible to prevent the first and second connection end surfaces 12 and 22 from being deformed or reduced by the repulsive force of the seal main body portion 31.

Further, by suppressing the warpage of the first and second connection end faces 12 and 22, the first and second connection portions 11 and 21 have the first clamp groove 13 and the first clamp groove 13 and the second after being pulled together, as shown in FIG. 2 The distance W1 between the clamp groove 23 and the clamp groove 23 is about the same as the inner diameter dimension W2 of the clamp member 40. Therefore, in the connection portion seal structure 1, the clamp member 40 can be easily attached to the first and second connection portions 11 and 21 connected via the seal main body portion 31. Further, since it is not necessary to improve the strength of the clamp member 40 so as to return the warpage of the first and second connection end faces 12 and 22, the wall thickness of the clamp member 40 and the first and second connection portions 11 and 21 is increased. The size can be reduced to make the connection portion seal structure 1 compact.

In addition to this, in the connection portion seal structure 1 of the present embodiment, the first and second outer annular walls 31m and 31n are allowed to be deformed by the gaps S1 to S4, and the first and second inner annular walls are allowed to be deformed by the gaps S5 and S6. Since the walls 31v and 31w are allowed to be deformed, the repulsive force generated by the seal body 31 when the first and second connection portions 11 and 21 are pulled through the seal body 31 can be reduced. By reducing the repulsive force in this way, the first and second connection portions 11 and 21 deform the first and second connection end faces 12 and 22 when they are connected via the seal main body portion 31. Is suppressed. Therefore, also in this respect, the wall thickness of the clamp member 40 and the first and second connecting portions 11 and 21 can be reduced to make the connecting portion sealing structure 1 compact.

Further, in the connection portion seal structure 1 of the present embodiment, the first and second outer tapered portions 14b and 24b and the first and second external pressure contact tapered portions 31p and 31q are the base ends of the first and second annular protrusions 17 and 27. Since the portions 17a and 27a are inclined at an acute angle, the first and second outer annular walls 31m and 31n tend to fall toward the base end portions 17a and 27a of the first and second annular projections 17 and 27. Therefore, according to the connection portion seal structure 1 of the present embodiment, the seal load F4 is efficiently raised by the collapse generated in the first and second outer pressure welding allowances P3 and P4, respectively, so that the first and second outer pressure welding allowances F4 are increased. Even if P3 and P4 are made smaller than the first and second inner taper pressure welding margins P1 and P2, the seal loads F3 and F4 become high, and fluid leakage can be reliably prevented.

<About surface pressure analysis>
The inventors performed a simulation for analyzing the surface pressure generated in the seal main body 31 for the connection portion seal structure 1 of the present embodiment. Since the first and second connection end faces 12 and 22 of the first and second connection portions 11 and 21 have the same shape and both end faces of the seal main body 31 have the same shape, the simulation is performed on the first connection end face 12. This was performed only on the first annular protrusion 17 and the first annular groove 31a side of the seal main body 31. The result of this surface pressure analysis is shown in FIG. In FIG. 9, the direction and strength of the surface pressure are represented by a bar graph, and the magnitude of the surface pressure is also represented by a gradation. In other words, the longer the bar graph and the darker the gradation, the greater the surface pressure.

As shown in FIG. 9, it can be seen that a strong surface pressure Z3 is generated at the portion P1a of the first inner taper pressure welding allowance P1 located on the tip end side of the first inner annular wall 31v. Further, the surface pressure Z3 is generated toward the I1 portion in the drawing near the connection position between the first annular groove 31a and the first positioning portion 31c. As a result, it can be seen that the surface pressure near the connection position between the first annular groove 31a and the first positioning portion 31c of the first inner seal pressure welding allowance P5 is increasing. Locally generating such a high surface pressure is a powerful sealing force for preventing fluid leakage. From this, in order to reduce the deflection of the first connecting portion 11, the portion P1b of the first inner taper pressure contact allowance P1 located on the back side of the tip of the first inner annular wall 31v is located on the tip side. It can be seen that the sealing force of the first inner seal pressure welding allowance P5 can be maintained high even if it is made smaller than the portion P1a.

Further, the surface pressure Z4 generated in the first outer pressure contact allowance P3 is generated toward the I2 portion in the figure near the connection position between the first annular groove 31a and the first positioning portion 31c. As a result, it can be seen that the surface pressure generated near the connection position between the first annular groove 31a and the first positioning portion 31c of the first outer seal pressure welding allowance P7 is increasing. Then, in the first inner seal pressure welding allowance P5 and the first outer seal pressure welding allowance P7, the tip portions of the first annular protrusion 17 are press-fitted by expanding the first annular groove 31a, so that the surface pressures Z1a and Z1b are increased. It occurs locally. As a result, in the first inner seal pressure welding allowance P5 and the first outer seal pressure welding allowance P7, high surface pressure is generated at four places, and each of them has a strong sealing force, so that fluid leakage can be prevented.

Then, the surface pressures Z1a and Z2a generated in the first inner seal pressure contact allowance P5 and the surface pressures Z1b and Z2b generated in the first outer seal pressure contact allowance P7 are symmetrically approximately the same in the radial inward direction and the outward direction. It has occurred. Further, the surface pressure Z3 generated in the first inner taper pressure contact allowance P1 and the surface pressure Z4 generated in the first outer pressure contact allowance P3 toward the first inner seal pressure contact allowance P5 and the first outer seal pressure contact allowance P7, respectively. , It occurs symmetrically with almost the same size. That is, the sealing force generated between the first and second connecting portions 11 and 21 and the seal main body portion 31 acts in a well-balanced manner in the radial inward direction and the radial direction outward direction. Therefore, it can be seen that in the connection portion seal structure 1, the portion of the first connection portion 11 to which the clamp member 40 is mounted is not easily deformed so as to warp, and the sealing force can be maintained at a certain level or more.

(Second Embodiment)
Subsequently, the second embodiment of the present invention will be described. FIG. 10 is a cross-sectional view showing a connection portion seal structure 1x according to a second embodiment of the present invention. FIG. 11 is an enlarged cross-sectional view of the seal ring 30x shown in FIG. 10 around the seal main body 31x. In FIG. 11, only the shape of the cross-sectional portion is shown, and hatching is omitted.

<Outline structure of connection part seal structure>
The connection portion seal structure 1x of the second embodiment has the same configuration as that of the first embodiment except for the seal main body portion 31x of the seal ring 30x. Here, the seal main body 31x will be mainly described. Regarding the configuration common to the first embodiment, the same reference numerals as those of the first embodiment are used in the drawings and description, and the description thereof will be omitted as appropriate.

The seal main body 31x shown in FIGS. 10 and 11 mainly includes first and second internal pressure welding tapered portions 31hx and 31ix, first and second external pressure welding tapered portions 31px and 31qx, and first and second inner pressure welding tapered portions 31px and 31qx. The point that the taper pressure welding allowances P1x and P2x and the first and second outer pressure welding allowances P3x and P4x are symmetrical with respect to the first and second annular protrusions 17 and 27 is the seal main body portion of the first embodiment. It is different from 31.

The first and second internal pressure welding tapered portions 31hx and 31ix are provided with a radial wall thickness slightly larger than that of the first and second internal pressure welding tapered portions 31h and 31i of the first embodiment. That is, the tip surfaces 31rx, 31sx of the first and second inner annular walls 31vx, 31wx are provided wider in the radial direction than the tip surfaces 31r, 31s of the first and second inner annular walls 31v, 31w of the first embodiment. Has been done.

The taper angles θ11x and θ12x of the first and second internal pressure contact tapered portions 31hx and 31ix are provided in the same manner as the taper angles θ11 and θ12 of the first embodiment. Therefore, as shown in FIG. 10, the first and second inner taper pressure contact allowances P1x and P2x of the first and second inner pressure contact taper portions 31hx and 31ix are closer to the tip surfaces 31rx and 31sx in the portions P1ax and P2ax. , It is provided larger than the portions P1bx and P2bx far from the tip surfaces 31rx and 31sx. That is, the first and second inner taper pressure contact allowances P1x and P2x become larger as they are closer to the base end portions 17a and 27a.

The first and second external pressure contact tapered portions 31px and 31qx shown in FIGS. 10 and 11 are provided with taper angles θ13x and θ14x smaller than the taper angles θ3 and θ4 of the first and second outer tapered portions 14b and 24b. .. Therefore, the first and second outer pressure contact allowances P3x and P4x of the first and second outer pressure contact tapered portions 31px and 31qx are the portions P3ax, close to the tip surfaces 31tx and 31ux of the first and second outer annular walls 31mx and 31nx. The P4ax is provided larger than the portions P3bx and P4bx far from the tip surfaces 31tx and 31ux of the first and second outer annular walls 31mx and 31nx. That is, the first and second outer pressure welding allowances P3x and P4x become larger as they are closer to the base end portions 17a and 27a.

The taper angles θ13x and θ14x of the first and second external pressure welding tapered portions 31px and 31qx are provided to be the same as the taper angles θ11x and θ12x of the first and second internal pressure welding tapered portions 31hx and 31ix. Therefore, as shown in FIG. 10, the first and second outer pressure contact allowances P3x and P4x of the first and second outer pressure contact taper portions 31px and 31qx are about the same as the first and second inner taper pressure contact allowances P1x and P2x. It is provided in the size of. The tip surfaces 31rx, 31sx of the first and second inner annular walls 31vx, 31wx and the tip surfaces 31tx, 31ux of the first and second outer annular walls 31mx, 31nx are provided at the same height, and the first and second outer rings are provided at the same height. No gap is formed between the tapered portions 14b and 24b and the first and second external pressure contact tapered portions 31px and 31qx.

As shown in FIG. 10, the first and second large diameter portions 31ex and 31fx are provided with radial width dimensions of the same degree as the radial width dimensions of the first and second annular protrusions 17 and 27. Therefore, the gaps S1x, S2x, S5x, and S6x are smaller than the gaps S1, S2, S5, and S6 of the first embodiment.

<About the force relationship in the connection part seal structure>
FIG. 12 shows a state in which the work of press-fitting the first and second annular protrusions 17 and 27 into the first and second annular grooves 31a and 31b is completed. FIG. 13 is a diagram for explaining the force relationship of the seal portion in the connection portion seal structure 1x shown in FIG. In addition, in FIG. 12 and FIG. 13, only the shape of the cross-sectional portion is shown in order to make the drawings easier to see.

As shown in FIG. 12, in the connection portion seal structure 1x of the present embodiment, when the first and second annular projections 17 and 27 are press-fitted into the first and second annular grooves 31a and 31b, the first and second internal pressure contact tapers are formed. The portions 31hx and 31ix are pressed against the first and second inner tapered portions 14a and 24a, and the first and second external pressure contact tapered portions 31px and 31qx are pressed against the first and second outer tapered portions 14b and 24b. As a result, the seal main body 31x is suppressed from being deformed by the first and second inner annular walls 31vx and 31wx and the first and second outer annular walls 31mx and 31nx.

As shown in FIG. 13, the seal main body 31x is closer to the base ends 17a and 27a of the first and second annular protrusions 17 and 27, and the radial thickness of the first and second support pieces 18 and 28 is increased. The closer to the portion where the thickness is increased, the larger the first and second inner taper pressure welding allowances P1x and P2x are. Therefore, the first and second inner taper pressure contact allowances P1x and P2x increase the pressure contact force F15 at the portions where the strength of the first and second support pieces 18 and 28 is strong. As a result, the first and second support pieces 18 and 28 are less likely to be deformed so as to narrow the flow path even when the repulsive force of the seal main body 31x acts, and the sealing force can be maintained.

The first and second outer pressure contact allowances P3x and P4x are provided to have the same size as the first and second inner taper pressure contact allowances P1x and P2x, and the pressure contact forces with respect to the first and second connection portions 11 and 21. F15 and F16 act to the same extent. Therefore, in the connection portion seal structure 1x, the surface pressure F12 is larger than the surface pressure F11, and as shown in FIG. 12, the first and second connection end surfaces 12 and 22 are easily deformed so as to warp.

However, in the connection portion seal structure 1 of the present embodiment, the taper angles θ13x and θ14x are smaller than the taper angles θ3 and θ4. Therefore, the seal body portion 31x has a high pressure contact force F16 of the first and second outer pressure contact margins P3x and P4x on the tip side of the first and second outer annular walls 31mx and 31nx, which are most deformed. The portion where the pressure contact force F16 is high corresponds to the base end portions 17a and 27a of the first and second annular projections 17 and 27, and is the portion having the higher strength among the first and second connecting portions 11 and 21. Therefore, in the first and second connecting portions 11 and 21, deformation of the first and second connecting end faces 12 and 22 is suppressed. As a result, as shown in FIG. 12, the deformation loads F31 and F32 that deform the first and second connection end faces 12 and 22 become smaller. Therefore, the load that attracts the first and second connecting portions 11 and 21 can be minimized so that the distance W1x of the first and second clamp grooves 13 and 23 matches the inner diameter dimension W2 of the clamp member 40.

Further, the surface pressures F11 applied to the first and second internal pressure contact tapered portions 31hx and 31ix by the first and second inner tapered portions 14a and 24a, and the first and second outer tapered portions 14b and 24b are the first and 24b. The surface pressures F12 applied to the second external pressure contact taper portions 31px and 31qx act toward the first and second inner seal pressure contact allowances P5 and P6 and the first and second outer seal pressure contact allowances P7 and P8, and are second. The seal loads F3 and F4 are increased near the connection position between the 1 annular groove 31a and the 1st positioning portion 31c. Therefore, in the connection portion sealing structure 1x, the sealing force can be maintained or increased with the minimum pressure contact forces F15 and F16.

<About surface pressure analysis>
The inventors performed a simulation to analyze the surface pressure generated in the seal portion for the connection portion seal structure 1x of the present embodiment. Similar to the first embodiment, this simulation was also performed only on the first annular projection 17 of the first connection end surface 12 and the first annular groove 31a side of the seal main body 31x. The result of this surface pressure analysis is shown in FIG. In FIG. 14, the direction and strength of the surface pressure are represented by a bar graph, and the magnitude of the surface pressure is also represented by a gradation. In other words, the longer the bar graph and the darker the gradation, the greater the surface pressure.

In the connection portion seal structure 1x, of the first inner taper pressure contact allowance P1x and the first outer pressure contact allowance P3x, the surface pressures Z3x and Z4x of the portions P1ax and P3ax near the base end portion 17a of the first annular projection 17 are higher. ing. Then, the high surface pressures Z3x and Z4x are generated toward the I1x portion in the figure and the I2x portion in the figure near the connection position between the first annular groove 31a and the first positioning portion 31c. As a result, it can be seen that the surface pressure generated in the first inner seal pressure welding allowance P5 increases. From this, in order to reduce the deflection of the first connecting portion 11, the portion P1bx of the first inner taper pressure contact allowance P1x located on the back side of the tip of the first inner annular wall 31vx is located on the tip side. It can be seen that the seal load F3 of the first inner seal pressure welding allowance P5 can be maintained even if the size is smaller than P1ax. Further, it can be seen that even if the first outer pressure contact allowance P3x is about the same as the first inner taper pressure contact allowance P1x, the surface pressure Z4x is generated toward the first outer seal pressure contact allowance P7. As a result, the taper angle θ13x is made smaller than the taper angle θ3 so that the first outer pressure contact allowance P3x becomes larger as it gets closer to the base end portion 17a, so that the first connection end surface 12 is deformed so as to warp. It can be seen that this can be suppressed and the decrease in sealing force can be reduced.

(Third Embodiment)
Subsequently, a third embodiment of the present invention will be described. FIG. 15 is an enlarged cross-sectional view of the connection portion seal structure 1y according to the third embodiment of the present invention, around the seal main body portion 31y. FIG. 16 is a front view of the seal ring 30y. FIG. 17 is a plan view of the seal ring 30y. FIG. 18 is a rear view of the seal ring 30y. FIG. 19 is a right side view of the seal ring 30y. FIG. 20 is a cross-sectional view taken along the line BB of FIG. FIG. 21 is a sectional view taken along line CC of FIG. FIG. 22 is a cross-sectional view taken along the line DD of FIG. FIG. 23 is a front perspective view of the seal ring 30y. The bottom view of the seal ring 30y is symmetrical with the plan view shown in FIG. 28, and the left side view is symmetrical with the right side view shown in FIG. 30, and is omitted.

<Outline structure of connection part seal structure>
The connection portion seal structure 1y of the third embodiment has the same configuration as that of the first embodiment except for the seal main body portion 31y. Here, the seal main body 31y will be mainly described. Regarding the configuration common to the first embodiment, the same reference numerals as those of the first embodiment are used in the drawings and description, and the description thereof will be omitted as appropriate.

The seal main body 31y shown in FIG. 15 includes the wall surfaces 19 and 29 in the flow path wall axis direction of the first and second outer mounting grooves 14d and 24d, and the wall surface in the flow path wall axis direction on the outer peripheral surface 31jy of the seal main body 30y. However, the fact that they are close to each other is different from the seal main body 31 of the first embodiment. That is, in the seal main body portion 31y, the radial wall thickness of the first and second outer annular walls 31m and 31ny is larger than the radial wall thickness of the first and second outer annular walls 31m and 31n of the first embodiment.

<About the force relationship in the connection part seal structure>
In the connection portion seal structure 1y of the third embodiment, the wall surfaces 19 and 29 in the axial direction of the flow path walls of the first and second mounting grooves 14 and 24 and the flow path wall axial direction on the outer peripheral surface 31jy of the seal main body portion 31y. When the first and second annular protrusions 17 and 27 are press-fitted into the seal-side pressure welding margins P5 to P7 of the first and second annular grooves 31a and 31b, the first and second annular protrusions 17 and 27 are close to each other. The outer annular walls 31my and 31ny are pushed outward in the radial direction by the first and second annular projections 17 and 27 to bring the outer peripheral surface 31jy into contact with the wall surfaces 19 and 29. As a result, surface pressure is generated toward the first and second annular protrusions 17 and 27 at the contact portions between the first and second outer annular walls 31my and 31ny and the wall surfaces 19 and 29. Therefore, the first and second outer annular walls 31my and 31ny are extruded toward the first and second annular projections 17 and 27.

For example, the first and second annular grooves 31a and 31b and the first and second annular protrusions 17 and 27 may be repeatedly attached and detached, or the first and second connecting portions 11 and 21 and the seal ring 30y may have an abnormal temperature. When exposed to changes, the pressure contact forces F6 of the first and second outer pressure contact margins P3 and P4 may decrease. Even in such a case, in the connection portion seal structure 1y of the present embodiment, the outer peripheral surfaces 31j come into contact with the wall surfaces 19 and 29, so that the first and second outer annular walls 31my and 31ny are brought into contact with the first and second annular projections 17, 27. It can be sufficiently pushed out to the side to suppress deformation of the seal body 31y, and the seal load F4 and the pressure contact force F6 can be maintained. Therefore, according to this embodiment, the sealing force can be secured as in the case of the temperature change in the initial state or the normal state.

The present invention is not limited to the above embodiment, and various applications are possible.

For example, the connection portion seal structure 1 may be applied, for example, when the seal ring 30 is arranged between the valve drive portion and the valve body.

For example, the connection portion seal structure 1 may be applied to piping or fluid control equipment applied to other than semiconductor manufacturing equipment.

For example, the seal main body 31 may omit the first and second large diameter portions 31e and 31f. Further, for example, in the seal main body portion 31, as shown in FIG. 24, the first external pressure contact tapered portion 31p may be directly connected to the outer peripheral surface 31j, and the first and second inclined portions 31k and 31l may be omitted.

For example, the first and second connection portions 11 and 21 may be PFA, and the seal ring 30 may be PTFE. Further, for example, the first and second connecting portions 11 and 21 and the seal ring 30 may be formed of the same material such as PFA or PTFE.

For example, the first and second connection end faces 12 and 22 of the first and second connection portions 11 and 21 do not have to have the same shape. Further, the seal main body 31 does not have to have the same shape on both end surfaces. For example, an inner taper portion, an outer taper portion, or the like is provided on either one of the first connection end surface 12 and the second connection end surface 22, and an inner pressure contact taper portion, an outer pressure contact taper portion, and the like are provided only on one end surface of the seal body portion 31. May be provided.

For example, the first and second outer pressure welding allowances P3, P4, P3x, P4x may include a portion generated by the distortion of the seal main body portions 31, 31x generated at the time of mounting. For example, as shown in FIG. 25, the seal main body portion 31 may be provided with a first external pressure contact tapered portion 31py so as to be recessed in an arc shape in a cross section toward the inside in the radial direction. Further, for example, as shown in FIG. 26, the seal main body portion 31 may be provided with the first external pressure contact tapered portion 31 pz so as to project in an arcuate cross section in the radial direction outward. Further, for example, contrary to these, the first external pressure contact tapered portion of the seal main body 31 is formed by a tapered surface, and the first connection portion 11 has an arcuate cross section at a position corresponding to the first external pressure contact tapered portion. The first outer tapered portion may be provided so as to project to the surface, or the first outer tapered portion may be provided so as to be recessed in an arc shape in cross section. That is, depending on the shape of the first outer tapered portion, the outer pressure contact allowance may be increased as it is closer to the base end portion.

For example, the taper angles θ1, θ2, θ3, θ4 are larger than the taper angles θ11, θ12, θ13, θ14, θ11x, θ12x, θ13x, θ14x, and the taper angles θ1, θ2, θ3, θ4 are 30 ° to 60 °. The taper angles θ11, θ12, θ13, θ14, θ11x, θ12x, θ13x, and θ14x may be 10 ° to 50 °. If the taper angle is too small, the wall thickness of each member becomes thin and the strength tends to be insufficient, and if the taper angle is too large, the surface pressure generated there is directed in the axial direction of the flow path walls 16a and 26a. This is because it may be difficult to maintain or increase the seal loads F3 and F4 because they are not oriented toward the 1st and 2nd annular protrusions 17 and 27.

For example, in the seal rings 30, 30x, 30y of the above-described form, the thickness, radial dimensions, etc. of the seal main body portion 31, 31x, 31y, the overhanging portion 32, and the grip portion 33 can be appropriately changed according to the dimensions of the mounting destination. Needless to say. For example, the seal ring 30 may have its thickness, radial dimensions, and the like changed as in the seal ring 30z shown in FIGS. 27 to 34. FIG. 27 is a front view of the seal ring 30z. FIG. 29 is a rear view of the seal ring 30z. FIG. 28 is a plan view of the seal ring 30z. FIG. 30 is a right side view of the seal ring 30z. FIG. 31 is a sectional view taken along line JJ of FIG. 27. FIG. 32 is a cross-sectional view taken along the line KK of FIG. 27. FIG. 33 is a cross-sectional view taken along the line LL of FIG. 27. FIG. 34 is a front perspective view of the seal ring 30z. The bottom view of the seal ring 30z is symmetrical with the plan view shown in FIG. 28, and the left side view is symmetrical with the right side view shown in FIG. 30, and is omitted.

For example, in the above-described embodiment and the modified examples shown in FIGS. 27 to 34, the overhanging portion 32 and the gripping portion 33 are integrally provided on the seal main body portions 31, 31x, 31y, but the overhanging portion 32 and the gripping portion 33 are provided. It may be omitted. That is, the seal rings 30, 30x, 30y, and 30z may not have the overhanging portion 32 and the gripping portion 33. Further, for example, the seal rings 30, 30x, 30y, and 30z may not have the grip portion 33.

1,1x, 1y Connection part Seal structure 11,21 1st and 2nd connection parts 12,22 1st and 2nd connection end faces 14,24 1st and 2nd mounting grooves 14a, 24a 1st and 2nd inner taper parts 14b, 24b 1st and 2nd outer taper portions 16,26 1st and 2nd flow paths 16a, 26a 1st and 2nd flow path walls 17, 27 1st and 2nd annular protrusions 31, 31x, 31y Seal body 31a, 31b 1st and 2nd annular grooves 31h, 31i 1st and 2nd internal pressure welding tapered portions 31p, 31q 1st and 2nd external pressure welding tapered portions P1, P2, P1x, P2x 1st and 2nd inner pressure welding taper P3, P4, P3x, P4x 1st and 2nd outer pressure contact allowances θ1 to θ4, θ11 to θ14, θ11x to θ14x Taper angle

Claims (8)

It connects the first connection part and the second connection part via a seal member.
Both or one of the connection end face of the first connection portion and the connection end face of the second connection portion
The flow path wall that opens to the connection end face and
An annular protrusion projecting along the axial direction of the flow path wall to the outside in the radial direction of the flow path wall,
It is provided with an inner mounting groove provided inside the annular protrusion in the radial direction.
The seal member
Formed in a ring
In a connection portion seal structure in which an annular groove into which the annular protrusion is press-fitted is provided on both end faces or one end surface.
The inner mounting groove is
Having an inner tapered portion provided at an acute angle with respect to the annular projection on the radial inside of the base end portion of the annular projection and connected to the flow path wall.
The inner peripheral surface of the seal member is
Having an internal pressure contact tapered portion formed along an end portion located on the end face side where the annular groove opens and inclined so as to press contact with the inner tapered portion.
The connection end face provided with the inner mounting groove is
Having an outer mounting groove provided on the radial outer side of the annular protrusion,
The seal member is
Having an outer pressure welding allowance that presses outward in the radial direction with respect to the inner wall of the outer mounting groove.
The outer pressure welding allowance is smaller than the inner taper pressure welding allowance for which the inner pressure welding tapered portion is pressed against the inner tapered portion.
The connection part seal structure is characterized by. In the connection portion seal structure according to claim 1,
The outer mounting groove is
Having an outer tapered portion provided at an acute angle with respect to the annular projection on the radial outer side of the base end portion of the annular projection.
The connection part seal structure is characterized by. In the connection portion seal structure according to claim 1 or 2.
The outer peripheral surface of the seal member is
A connection portion seal structure characterized by having an external pressure contact tapered portion formed along an end portion located on the end face side where the annular groove opens . In the connection portion seal structure according to any one of claims 1 to 3 .
The sealing member is a base of the annular protrusion when the annular protrusion is press-fitted into the annular groove.
Forming an annular gap with the end,
The connection part seal structure is characterized by. In the connection portion seal structure according to any one of claims 1 to 4 .
A support piece that supports the end of the inner peripheral surface of the seal member is provided in an annular shape along the flow path wall by the inner taper portion, and the radial thickness of the portion located on the base end side of the annular protrusion. The thickness is larger than the radial wall thickness of the portion located on the tip end side of the annular protrusion.
The connection part seal structure is characterized by. In the connection portion seal structure according to any one of claims 1 to 5.
The position of the outer pressure welding allowance is closer to the base end portion of the annular projection than the seal pressure welding allowance where the inner wall of the annular groove and the annular projection are in pressure contact.
The connection part seal structure is characterized by. In the connection portion seal structure according to any one of claims 1 to 6.
The sealing member has a connection portion sealing structure, wherein an outer peripheral surface located on the outer side in the radial direction includes a surface close to a surface of the outer mounting groove along the axial direction. A seal member used in the connection portion seal structure according to any one of claims 1 to 7.

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